关键词: 钉螺；历史有螺环境；宝山区

Abstract: Objective To understand the distribution and characteristics of historical Oncomelania hupensis snail environments in Baoshan District， Shanghai City， so as to provide the reference for adjusting and formulating the monitoring program of the snail situation in the future. Methods A retrospective survey and a field survey were conducted to collect the information of historical O. hupensis snail environments and set up the database. The distribution and characteristics of them were analyzed. Results There were 53 historical O. hupensis snail environments which distributed in three towns， and the accumulative area was 1 635 530 m2 in Baoshan District， Shanghai City. Class I， II， III and IV accounted for 73.58%， 5.66%， 16.98% and 3.77% respectively. The complete transformation （Class I and Class II） was done in 42 places which covered the area of 1 622 043 m2， in which Class I environments and Class II environments accounted for 79.25% and 99.18% of the total， respectively. Conclusions There has been a great change in the historical O. hupensis snail environments in Baoshan District， Shanghai City. The information of the field investigation should be enriched and updated at different times to guide the investigation of O. hupensis snails in the future.

Key words: Oncomelania snail； Historical snail environment； Baoshan District